Gripping is an art in itself. The strength of grip used by a competition fighter on its own is enough to negate almost anything that an untrained person could probably do - in the same way that Iwama stylists work ferociously on their 'grabbing' skills but to a higher degree.

However at the base level Judo generally has one basic fault - a lack of defence against head striking (headbutts are very common but constant strikes to the head can put someone on the back foot).

And Aikido generally has a major fault in the lack of dynamic resistance.

This is why cross training, communication and threads like this are in the main helpful. We all have our own obsessions, but it is all too easy to become transfixed on small things when large things go un-noticed. And in the case of Aikido there are so many schools that a determined practioner can find these faults and overcome them, but this requires the same kind of open-mindedness that it takes to appreciate Judo/Karate/BJJ/et al.